The Green Bay Packers run defense has been insanely dominant this season, allowing just 1.99 yards per carry and 157 rushing yards through four games. Since 1940, only one team — the 1995 49ers — have allowed fewer rushing yards through four games. And Green Bay is the first team since 1953 to allow less than two yards per carry through four games!

Making this all the more remarkable is that the Packers run defense was bad last season, ranking in the bottom half of the league in both rushing yards and rushing touchdowns, and 29th in yards per carry. From a snap count perspective, LB Nick Perry (76%), LB Jake Ryan (73%), DT Mike Daniels (64%), and LB Blake Martinez (52%) are the only front seven defenders to have appeared in at least 50% of the team’s plays! In other words, it’s not like guys like Clay Matthews (47%) and Julius Peppers (44%) are having monster seasons.

Frankly, I haven’t watched enough of the Packers defense to weigh in on what’s going on — I don’t know if Perry or Ryan is having a breakout season.  So instead, here’s what I’ll do.  The graph below shows the percentage of running plays against the Packers that have gone for X yards, and also against the rest of the NFL.  Here’s the key: the Packers have been incredible at dropping opposing carries for a loss (28%) compared to the rest of the NFL (13%).  Meanwhile, 11% of all runs against the other 31 teams have gone for at least 10+ yards, compared to just two percent of all runs for the Packers (with a long of just 14 yards).

So what’s the takeaway? Does this graph make you think the Packers’ run defense success is more or less fluky (given that there’s always a large amount of flukiness present in such an outlier result)?